ref: 84cdb4e2e9e1712fc913c05c38f3cf94ca100e5d
dir: /code/renderer/tr_light.c/
/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
This file is part of Quake III Arena source code.
Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.
Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
// tr_light.c
#include "tr_local.h"
#define DLIGHT_AT_RADIUS 16
// at the edge of a dlight's influence, this amount of light will be added
#define DLIGHT_MINIMUM_RADIUS 16
// never calculate a range less than this to prevent huge light numbers
/*
===============
R_TransformDlights
Transforms the origins of an array of dlights.
Used by both the front end (for DlightBmodel) and
the back end (before doing the lighting calculation)
===============
*/
void R_TransformDlights( int count, dlight_t *dl, orientationr_t *or) {
int i;
vec3_t temp;
for ( i = 0 ; i < count ; i++, dl++ ) {
VectorSubtract( dl->origin, or->origin, temp );
dl->transformed[0] = DotProduct( temp, or->axis[0] );
dl->transformed[1] = DotProduct( temp, or->axis[1] );
dl->transformed[2] = DotProduct( temp, or->axis[2] );
}
}
/*
=============
R_DlightBmodel
Determine which dynamic lights may effect this bmodel
=============
*/
void R_DlightBmodel( bmodel_t *bmodel ) {
int i, j;
dlight_t *dl;
int mask;
msurface_t *surf;
// transform all the lights
R_TransformDlights( tr.refdef.num_dlights, tr.refdef.dlights, &tr.or );
mask = 0;
for ( i=0 ; i<tr.refdef.num_dlights ; i++ ) {
dl = &tr.refdef.dlights[i];
// see if the point is close enough to the bounds to matter
for ( j = 0 ; j < 3 ; j++ ) {
if ( dl->transformed[j] - bmodel->bounds[1][j] > dl->radius ) {
break;
}
if ( bmodel->bounds[0][j] - dl->transformed[j] > dl->radius ) {
break;
}
}
if ( j < 3 ) {
continue;
}
// we need to check this light
mask |= 1 << i;
}
tr.currentEntity->needDlights = (mask != 0);
// set the dlight bits in all the surfaces
for ( i = 0 ; i < bmodel->numSurfaces ; i++ ) {
surf = bmodel->firstSurface + i;
if ( *surf->data == SF_FACE ) {
((srfSurfaceFace_t *)surf->data)->dlightBits[ tr.smpFrame ] = mask;
} else if ( *surf->data == SF_GRID ) {
((srfGridMesh_t *)surf->data)->dlightBits[ tr.smpFrame ] = mask;
} else if ( *surf->data == SF_TRIANGLES ) {
((srfTriangles_t *)surf->data)->dlightBits[ tr.smpFrame ] = mask;
}
}
}
/*
=============================================================================
LIGHT SAMPLING
=============================================================================
*/
extern cvar_t *r_ambientScale;
extern cvar_t *r_directedScale;
extern cvar_t *r_debugLight;
/*
=================
R_SetupEntityLightingGrid
=================
*/
static void R_SetupEntityLightingGrid( trRefEntity_t *ent ) {
vec3_t lightOrigin;
int pos[3];
int i, j;
byte *gridData;
float frac[3];
int gridStep[3];
vec3_t direction;
float totalFactor;
if ( ent->e.renderfx & RF_LIGHTING_ORIGIN ) {
// seperate lightOrigins are needed so an object that is
// sinking into the ground can still be lit, and so
// multi-part models can be lit identically
VectorCopy( ent->e.lightingOrigin, lightOrigin );
} else {
VectorCopy( ent->e.origin, lightOrigin );
}
VectorSubtract( lightOrigin, tr.world->lightGridOrigin, lightOrigin );
for ( i = 0 ; i < 3 ; i++ ) {
float v;
v = lightOrigin[i]*tr.world->lightGridInverseSize[i];
pos[i] = floor( v );
frac[i] = v - pos[i];
if ( pos[i] < 0 ) {
pos[i] = 0;
} else if ( pos[i] >= tr.world->lightGridBounds[i] - 1 ) {
pos[i] = tr.world->lightGridBounds[i] - 1;
}
}
VectorClear( ent->ambientLight );
VectorClear( ent->directedLight );
VectorClear( direction );
assert( tr.world->lightGridData ); // bk010103 - NULL with -nolight maps
// trilerp the light value
gridStep[0] = 8;
gridStep[1] = 8 * tr.world->lightGridBounds[0];
gridStep[2] = 8 * tr.world->lightGridBounds[0] * tr.world->lightGridBounds[1];
gridData = tr.world->lightGridData + pos[0] * gridStep[0]
+ pos[1] * gridStep[1] + pos[2] * gridStep[2];
totalFactor = 0;
for ( i = 0 ; i < 8 ; i++ ) {
float factor;
byte *data;
int lat, lng;
vec3_t normal;
#if idppc
float d0, d1, d2, d3, d4, d5;
#endif
factor = 1.0;
data = gridData;
for ( j = 0 ; j < 3 ; j++ ) {
if ( i & (1<<j) ) {
factor *= frac[j];
data += gridStep[j];
} else {
factor *= (1.0f - frac[j]);
}
}
if ( !(data[0]+data[1]+data[2]) ) {
continue; // ignore samples in walls
}
totalFactor += factor;
#if idppc
d0 = data[0]; d1 = data[1]; d2 = data[2];
d3 = data[3]; d4 = data[4]; d5 = data[5];
ent->ambientLight[0] += factor * d0;
ent->ambientLight[1] += factor * d1;
ent->ambientLight[2] += factor * d2;
ent->directedLight[0] += factor * d3;
ent->directedLight[1] += factor * d4;
ent->directedLight[2] += factor * d5;
#else
ent->ambientLight[0] += factor * data[0];
ent->ambientLight[1] += factor * data[1];
ent->ambientLight[2] += factor * data[2];
ent->directedLight[0] += factor * data[3];
ent->directedLight[1] += factor * data[4];
ent->directedLight[2] += factor * data[5];
#endif
lat = data[7];
lng = data[6];
lat *= (FUNCTABLE_SIZE/256);
lng *= (FUNCTABLE_SIZE/256);
// decode X as cos( lat ) * sin( long )
// decode Y as sin( lat ) * sin( long )
// decode Z as cos( long )
normal[0] = tr.sinTable[(lat+(FUNCTABLE_SIZE/4))&FUNCTABLE_MASK] * tr.sinTable[lng];
normal[1] = tr.sinTable[lat] * tr.sinTable[lng];
normal[2] = tr.sinTable[(lng+(FUNCTABLE_SIZE/4))&FUNCTABLE_MASK];
VectorMA( direction, factor, normal, direction );
}
if ( totalFactor > 0 && totalFactor < 0.99 ) {
totalFactor = 1.0f / totalFactor;
VectorScale( ent->ambientLight, totalFactor, ent->ambientLight );
VectorScale( ent->directedLight, totalFactor, ent->directedLight );
}
VectorScale( ent->ambientLight, r_ambientScale->value, ent->ambientLight );
VectorScale( ent->directedLight, r_directedScale->value, ent->directedLight );
VectorNormalize2( direction, ent->lightDir );
}
/*
===============
LogLight
===============
*/
static void LogLight( trRefEntity_t *ent ) {
int max1, max2;
if ( !(ent->e.renderfx & RF_FIRST_PERSON ) ) {
return;
}
max1 = ent->ambientLight[0];
if ( ent->ambientLight[1] > max1 ) {
max1 = ent->ambientLight[1];
} else if ( ent->ambientLight[2] > max1 ) {
max1 = ent->ambientLight[2];
}
max2 = ent->directedLight[0];
if ( ent->directedLight[1] > max2 ) {
max2 = ent->directedLight[1];
} else if ( ent->directedLight[2] > max2 ) {
max2 = ent->directedLight[2];
}
ri.Printf( PRINT_ALL, "amb:%i dir:%i\n", max1, max2 );
}
/*
=================
R_SetupEntityLighting
Calculates all the lighting values that will be used
by the Calc_* functions
=================
*/
void R_SetupEntityLighting( const trRefdef_t *refdef, trRefEntity_t *ent ) {
int i;
dlight_t *dl;
float power;
vec3_t dir;
float d;
vec3_t lightDir;
vec3_t lightOrigin;
// lighting calculations
if ( ent->lightingCalculated ) {
return;
}
ent->lightingCalculated = qtrue;
//
// trace a sample point down to find ambient light
//
if ( ent->e.renderfx & RF_LIGHTING_ORIGIN ) {
// seperate lightOrigins are needed so an object that is
// sinking into the ground can still be lit, and so
// multi-part models can be lit identically
VectorCopy( ent->e.lightingOrigin, lightOrigin );
} else {
VectorCopy( ent->e.origin, lightOrigin );
}
// if NOWORLDMODEL, only use dynamic lights (menu system, etc)
if ( !(refdef->rdflags & RDF_NOWORLDMODEL )
&& tr.world->lightGridData ) {
R_SetupEntityLightingGrid( ent );
} else {
ent->ambientLight[0] = ent->ambientLight[1] =
ent->ambientLight[2] = tr.identityLight * 150;
ent->directedLight[0] = ent->directedLight[1] =
ent->directedLight[2] = tr.identityLight * 150;
VectorCopy( tr.sunDirection, ent->lightDir );
}
// bonus items and view weapons have a fixed minimum add
if ( 1 /* ent->e.renderfx & RF_MINLIGHT */ ) {
// give everything a minimum light add
ent->ambientLight[0] += tr.identityLight * 32;
ent->ambientLight[1] += tr.identityLight * 32;
ent->ambientLight[2] += tr.identityLight * 32;
}
//
// modify the light by dynamic lights
//
d = VectorLength( ent->directedLight );
VectorScale( ent->lightDir, d, lightDir );
for ( i = 0 ; i < refdef->num_dlights ; i++ ) {
dl = &refdef->dlights[i];
VectorSubtract( dl->origin, lightOrigin, dir );
d = VectorNormalize( dir );
power = DLIGHT_AT_RADIUS * ( dl->radius * dl->radius );
if ( d < DLIGHT_MINIMUM_RADIUS ) {
d = DLIGHT_MINIMUM_RADIUS;
}
d = power / ( d * d );
VectorMA( ent->directedLight, d, dl->color, ent->directedLight );
VectorMA( lightDir, d, dir, lightDir );
}
// clamp ambient
for ( i = 0 ; i < 3 ; i++ ) {
if ( ent->ambientLight[i] > tr.identityLightByte ) {
ent->ambientLight[i] = tr.identityLightByte;
}
}
if ( r_debugLight->integer ) {
LogLight( ent );
}
// save out the byte packet version
((byte *)&ent->ambientLightInt)[0] = myftol( ent->ambientLight[0] );
((byte *)&ent->ambientLightInt)[1] = myftol( ent->ambientLight[1] );
((byte *)&ent->ambientLightInt)[2] = myftol( ent->ambientLight[2] );
((byte *)&ent->ambientLightInt)[3] = 0xff;
// transform the direction to local space
VectorNormalize( lightDir );
ent->lightDir[0] = DotProduct( lightDir, ent->e.axis[0] );
ent->lightDir[1] = DotProduct( lightDir, ent->e.axis[1] );
ent->lightDir[2] = DotProduct( lightDir, ent->e.axis[2] );
}
/*
=================
R_LightForPoint
=================
*/
int R_LightForPoint( vec3_t point, vec3_t ambientLight, vec3_t directedLight, vec3_t lightDir )
{
trRefEntity_t ent;
// bk010103 - this segfaults with -nolight maps
if ( tr.world->lightGridData == NULL )
return qfalse;
Com_Memset(&ent, 0, sizeof(ent));
VectorCopy( point, ent.e.origin );
R_SetupEntityLightingGrid( &ent );
VectorCopy(ent.ambientLight, ambientLight);
VectorCopy(ent.directedLight, directedLight);
VectorCopy(ent.lightDir, lightDir);
return qtrue;
}